The bukkit-for-clojure-template from cpmcdaniel

Error: NullPointerException in the Event Handler

Hello,
first of all: A big thanks for driving this project forward.
I am posting this here because issues seem to be disabled on your Bukkit4Clojure fork
When I generate a new lein project according to your instructions and then trying to put the example event handler code in it,
I cannot produce the uberjar of my project. While compiling, the error log is as following:

{:clojure.main/message
 "Execution error (NullPointerException) at bukkitclj.event/register-event (event.clj:48).\nnull\n",
 :clojure.main/triage
 {:clojure.error/class java.lang.NullPointerException,
  :clojure.error/line 48,
  :clojure.error/symbol bukkitclj.event/register-event,
  :clojure.error/source "event.clj",
  :clojure.error/phase :execution},
 :clojure.main/trace
 {:via
  [{:type clojure.lang.Compiler$CompilerException,
    :message "Syntax error macroexpanding at (plugin.clj:19:1).",
    :data
    {:clojure.error/phase :execution,
     :clojure.error/line 19,
     :clojure.error/column 1,
     :clojure.error/source "plugin.clj"},
    :at [clojure.lang.Compiler$InvokeExpr eval "Compiler.java" 3707]}
   {:type java.lang.NullPointerException,
    :at [bukkitclj.event$register_event invokeStatic "event.clj" 48]}],
  :trace
  [[bukkitclj.event$register_event invokeStatic "event.clj" 48]
   [bukkitclj.event$register_event invoke "event.clj" 36]
   [bukkitclj.event$register_event invokeStatic "event.clj" 40]
   [bukkitclj.event$register_event invoke "event.clj" 36]
   [lobbymania.plugin$fn__472 invokeStatic "plugin.clj" 20]
   [lobbymania.plugin$fn__472 invoke "plugin.clj" 19]
   [clojure.lang.AFn applyToHelper "AFn.java" 152]
   [clojure.lang.AFn applyTo "AFn.java" 144]
   [clojure.lang.Compiler$InvokeExpr eval "Compiler.java" 3702]
   [clojure.lang.Compiler compile1 "Compiler.java" 7731]
   [clojure.lang.Compiler compile "Compiler.java" 7798]
   [clojure.lang.RT compile "RT.java" 411]
   [clojure.lang.RT load "RT.java" 457]
   [clojure.lang.RT load "RT.java" 424]
   [clojure.core$load$fn__6839 invoke "core.clj" 6126]
   [clojure.core$load invokeStatic "core.clj" 6125]
   [clojure.core$load doInvoke "core.clj" 6109]
   [clojure.lang.RestFn invoke "RestFn.java" 408]
   [clojure.core$load_one invokeStatic "core.clj" 5908]
   [clojure.core$compile$fn__6844 invoke "core.clj" 6136]
   [clojure.core$compile invokeStatic "core.clj" 6136]
   [clojure.core$compile invoke "core.clj" 6128]
   [user$eval155$fn__164 invoke "form-init1447454908815526697.clj" 1]
   [user$eval155 invokeStatic "form-init1447454908815526697.clj" 1]
   [user$eval155 invoke "form-init1447454908815526697.clj" 1]
   [clojure.lang.Compiler eval "Compiler.java" 7177]
   [clojure.lang.Compiler eval "Compiler.java" 7167]
   [clojure.lang.Compiler eval "Compiler.java" 7167]
   [clojure.lang.Compiler load "Compiler.java" 7636]
   [clojure.lang.Compiler loadFile "Compiler.java" 7574]
   [clojure.main$load_script invokeStatic "main.clj" 475]
   [clojure.main$init_opt invokeStatic "main.clj" 477]
   [clojure.main$init_opt invoke "main.clj" 477]
   [clojure.main$initialize invokeStatic "main.clj" 508]
   [clojure.main$null_opt invokeStatic "main.clj" 542]
   [clojure.main$null_opt invoke "main.clj" 539]
   [clojure.main$main invokeStatic "main.clj" 664]
   [clojure.main$main doInvoke "main.clj" 616]
   [clojure.lang.RestFn applyTo "RestFn.java" 137]
   [clojure.lang.Var applyTo "Var.java" 705]
   [clojure.main main "main.java" 40]],
  :phase :execution}}

From plugin.clj:

(ns lobbymania.plugin
  (:gen-class
   :name lobbymania.Lobbymania
   :extends bukkitclj.ClojurePlugin)
  (:import [org.bukkit.plugin.java JavaPlugin]))

(set! *warn-on-reflection* true)

(defn -onEnable [^JavaPlugin this]
  (.. this (getLogger) (info "Clojure plugin Lobbymania enabled")))

(defn -onDisable [^JavaPlugin this])

(require '[bukkitclj.event :as ev])
(require '[bukkitclj.repl])
(ev/find-event "player-toggle")
(ev/describe-event :player/player-toggle-sneak)
;; use a reference to your own plugin instance here...
(let [plugin (deref bukkitclj.repl/plugin-ref)]
  (ev/register-event plugin
                     :player/player-toggle-sneak
                     (fn [e] (println "event triggered!"))
                     :priority/normal))

I looked at the event.clj file line 48, where it says:

(bk/plugin-manager)

But this refers to bukkit.clj which contains the macro
I do not know why the compiler even tries to runtime-check the value of plugin-manager against null, as this variable will be set on runtime and can never be initialized in an isolated environment.
Maybe I am getting something wrong here though, correct me if i do 😄

Thanks for looking into this,
m0rtis0

cpmcdaniel / bukkit-for-clojure-template Goto Github PK

bukkit-for-clojure-template's People

Contributors

Watchers

bukkit-for-clojure-template's Issues

Error: NullPointerException in the Event Handler

Recommend Projects

React

Vue.js

Typescript

TensorFlow

Django

Laravel

D3

Recommend Topics

javascript

web

server

Machine learning

Visualization

Game

Recommend Org

Facebook

Microsoft

Google

Alibaba

D3

Tencent